1. Field of the Invention
This invention relates to a printing method and a printing program for printing onto creased paper.
2. Description of the Prior Art
With the diversification of printing and improvement of printing quality in recent years, there has been a demand for making original book covers. Since a book cover is normally used to cover a book or other printed matter, strong durability is required and in terms of paper quality, a paper that is rather thick and exhibits a strong repulsive force against bending, in other words, has stiffness is preferable to be used. A book cover paper can thus be fitted to printed matter readily and yet in a manner that is pleasing to the eye by being subject in advance to a creasing to the size and shape of the printed matter. Creasing refers to a process of forming folds to make a paper foldable readily by pressure, etc.
In general, a conventional printer performs printing by moving a head in a main scanning direction while feeding a paper in a sub scanning direction and thus has a paper feeding mechanism. Since a paper feeding mechanism normally feeds a paper in the sub scanning direction by rotating a plurality of rollers, etc., the paper which is to be printed on is preferably flat without any folds, etc. Printing onto a book cover or other paper that has been creased in advance was thus not considered.
However, in using the conventional printer, when printing is started onto an original book cover, such as that described above, with folded portions as they are, the folded portions of the paper become close in distance to the head and the paper thus causes so-called head rubbing, which leads to lowering of image quality. Furthermore, depending on the degree of folding of the folded portions of the paper, the head that moves in the main scanning direction may collide with the paper. Such collision may cause not just damage in the paper but may also cause damage of the collided head itself since, as mentioned above, paper that is thick and highly strong in terms of paper quality is used.
Also in some printer models of the conventional printer cannot perform such printing onto an original book cover, such as that described above, because the printing range is too long with respect to the sub scanning direction in comparison to a normal, regular paper. That is, skewing (oblique deviation of the paper with respect to a paper feeding direction) due to a long length of a paper occurs during printing at a rear end of a book cover paper or other paper of long length that is not supported at either end, unlike a roll paper which, though being long in length, is supported by a roll at one end. Printing onto such paper is thus prohibited in some cases to prevent the degradation of printing quality or to prevent unwanted paper jam. Also in using the conventional printer to print onto an original book cover paper, shortage of the memory capacity may occur due to an increase in the data quantity. It is thus considered that there exist models with which printing across a range that far exceeds that of a regular paper is prohibited as an inherent specification.
Furthermore, in using the conventional printer to print onto an original book cover, because the printing range is too long with respect to the sub scanning direction in comparison to a normal regular paper, skewing occurs more readily than in printing onto single sheets due to inadequate pressing by roller pressure. It is also considered that tension cannot be applied readily as in the case of a roll paper.